1. Field of the Invention
This disclosure relates to systems for dispensing liquids from bags, in particular to a liquid dispensing system wherein liquid is dispensed from a bag via a puncturing device utilizing a single spike having a plurality of channels.
2. Description of the Related Art
Conventional domestic liquid dispensers used primarily for providing heated or cooled water are usually free standing devices which dispense sterilized or mineral water from large rigid water bottles. The rigid water bottles have a large body portion and a narrow neck portion having a mouth opening, and are coupled to a water dispenser by inverting the bottle and positioning the mouth of the bottle in a chamber of the water dispenser. Air, introduced into the water bottle through the mouth, allows water to be dispensed from the inverted bottle until the water level in the chamber reaches the mouth of the bottle. Since the water bottle is rigid, once the water level in the chamber reaches the mouth of the bottle no more air can enter the bottle, so water remaining in the inverted bottle is retained in the bottle due to the difference between the air pressure external to the inverted bottle and the air pressure inside the bottle.
Water is then dispensed from the chamber through a conduit attached to a valve at the opposite end of the chamber from the mouth of the water bottle. When the level of water in the chamber falls below the mouth of the water bottle, air enters the water bottle, allowing water to flow from the bottle until the water level in the chamber again reaches the mouth of the bottle.
Although conventional domestic water dispensers are widely used, they are deficient in a number of respects. First, water bottles used in the conventional domestic water dispensers usually contain a large quantity of sterilized water, typically on the order of about five (5) gallons. A gallon of water weighs about 8.39 pounds, and thus a full five gallon bottle weighs well in excess of forty (40) pounds. Due to the weight and size of a bottle holding that amount of water, it is often difficult to invert and properly locate the mouth of the bottle in the chamber without spilling a quantity of the water.
Second, to prevent water from continuously flowing from the water bottle while the water bottle is inverted, the water bottles used with such water dispensers are fabricated from a thick, rigid, plastic material that can hold a vacuum without collapsing. Such bottles are expensive and due to their cost, are usually resterilized and reused after an initial use. Because the bottles are rigid and enclosed, they are not collapsible or stackable, and require a great deal of space to transport, driving up the cost of shipping the empty water bottle back to the supplier for sterilization and reuse. These costs are adsorbed by the consumer through increased water costs.
Third, in order for the mouth of the water bottle to be positioned in the chamber of the cooler, the water bottles must have a neck, as described above. The presence of the neck, however, increases the difficulty in sterilizing the water bottles, since the neck may limit the ability of the sterilizing agents to reach all the interior parts of the bottle, even when large quantities of sterilizing agents are used. While the use of heat sterilization could overcome this problem to some extent, it is generally not possible to use heat sterilization on plastic bottles. Although sterilization using ultraviolet light is possible, ultraviolet light sterilization may lead to incomplete sterilization. Particularly troublesome, once the bottle is inverted into the fluid dispenser, the outside of the neck of the bottle can contact the fluid, and it is very difficult to maintain this area of the bottle sterile.
Fourth, with the necessity of sterilizing the water bottles after each use, over time the rigid plastic water bottles may develop cracks or holes. If such failures occur while the water bottle is inverted in the water dispenser, air will enter the water bottle and allow water to flow uncontrollably from the mouth of the water bottle, allowing the chamber eventually to overflow. This water overflow can expose the purchaser's premises to the risk of water damage.
One solution to the problem of potential chamber overflow, and the necessity to make bottles of rigid materials to allow for the pressure differential described above, is to add a valve in the flow path between the bottle and the chamber. Such a valve allows the flow of water out of the bottle to be closed off so that the chamber does not overflow. Such a valve can operate automatically, opening and closing depending on the level of the fluid in the chamber
A more recent development in fluid dispensing systems has been to utilize bags rather than bottles to transport and dispense water from an otherwise conventional fluid dispensing system (“office cooler”). Such a system is described in U.S. patent application Ser. No. 10/940,057 to Macler, et al., for example, the entire disclosure of which is incorporated herein by reference. The Macler application offers a device that dispenses fluid from a disposable or recyclable bag, and thereby affords some of the benefits associated therewith.
As described in the Macler application, however, to overcome the problem of over flowing the chamber since a collapsible bag cannot hold a reduced pressure headspace (as a rigid bottle does), the device described therein uses a vent to permit and control flow between the bag and the chamber. The vent runs parallel to the cooler's vertical axis, into which water flows when water is dispensed until the water level in the vent is level with the water level in the cooler. Such a vent straw equalizes the pressure within the bag with the ambient pressure.